Video gaming machines such as slot machines or video poker have long been a staple for the gaming industry. The profitability of a machine for operators is directly related to how popular that machine is to players. Competition for a more popular design among manufacturers is high, and a more popular game provides a substantial marketplace advantage. Popularity of a machine is often a function of both the perceived likelihood of winning and the entertainment value of the game itself.
One method of increasing both entertainment value and perceived likelihood of winning is the prevalent use of a bonus round. These designs allow a player to win a free game, either the same as the base game or a different game. Often times game establishments are limited in the number of machines they are able to provide; either due to floor space limitations or government regulation. For this reason it is important to maximize the profitability of each individual machine. For example, one player on one machine betting a dollar per play is as profitable as twenty players on twenty machines betting a nickel per play.